• Title/Summary/Keyword: form material

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Influence of the material for preformed moulds on the polymerization temperature of resin materials for temporary FPDs

  • Pott, Philipp-Cornelius;Schmitz-Watjen, Hans;Stiesch, Meike;Eisenburger, Michael
    • The Journal of Advanced Prosthodontics
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    • v.9 no.4
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    • pp.294-301
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    • 2017
  • PURPOSE. Temperature increase of $5.5^{\circ}C$ can cause damage or necrosis of the pulp. Increasing temperature can be caused not only by mechanical factors, e.g. grinding, but also by exothermic polymerization reactions of resin materials. The aim of this study was to evaluate influences of the form material on the intrapulpal temperature during the polymerization of different self-curing resin materials for temporary restorations. MATERIALS AND METHODS. 30 provisonal bridges were made of 5 resin materials: Prevision Temp (Pre), Protemp 4 (Pro), Luxatemp Star (Lux), Structure 3 (Str) and an experimental material (Exp). Moulds made of alginate (A) and of silicone (S) and vacuum formed moulds (V) were used to build 10 bridges each on a special experimental setup. The intrapulpal temperatures of three abutment teeth (a canine, a premolar, and a molar,) were measured during the polymerization every second under isothermal conditions. Comparisons of the maximum temperature ($T_{Max}$) and the time until the maximum temperature ($t_{TMax}$) were performed using ANOVA and Tukey Test. RESULTS. Using alginate as the mould material resulted in a cooling effect for every resin material. Using the vacuum formed mould, $T_{Max}$ increased significantly compared to alginate (P<.001) and silicone (P<.001). In groups Lux, Pro, and Pre, $t_{TMax}$ increased when the vacuum formed moulds were used. In groups Exp and Str, there was no influence of the mould material on $t_{TMax}$. CONCLUSION. All of the mould materials are suitable for clinical use if the intraoral application time does not exceed the manufacturer's instructions for the resin materials.

The property of WC(Co 0.5%) ultra precision turning for optical pick-up objective lens molding press for optical infomation storing(I) (광정보저장용 광픽업 대물렌즈 성형용 초경합금 (Co 0.5%) 초정밀절삭 특성(I))

  • Kim, Min-Jae;Lee, Jun-Key;Hwang, Yeon;Kim, Hye-Jeong;Kim, Jeong-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.178-178
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    • 2009
  • High-density optical information storing equipment, which is using Blu-ray, is the next generation information storing equipment that has about form six times to thirty-five times capacities. and high-density optical information storing equipment uses high NA(Numerical Aperture) aspheric glass objective lens as optical pick-up equipment to record and recognize high-density date. Generally this objective lens is developed and produced through a way of GMP(Glass Molding Press) that uses molding core that is performde by Ultra precision grinding, but grinding performing that has high-accuracy is very difficult because objective lens form is high NA. In this research, we preformed Ultra precision turning, using single crystal diamond bite, about WC(Co 0.5%), sintering brittleness material that is used molding core's material for GMP. and we confirmed aspheric glass lens compression of deformities molding core's Ultra precision turning possibility by measuring surface roughness(Ra) and processing surface's condition.

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Transformable Design in Contemporary Fashion (현대패션에 나타난 트랜스포머블 디자인)

  • Lim, Byung-Soo;Yim, Eun-Hyuk
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.3
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    • pp.29-43
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    • 2015
  • This study investigates transformable designs in contemporary fashion. In contemporary society, designs are accompanied by various changes such as transformation of shapes or variation of material beyond the certain form of dress. As a result of having interest in transformable designs with the various attempts on the overall design, transformable design is being suggested as an attempt as the new manner, radical concept, or alternative of multi-purpose lifestyle. With the constant research and collection presentation by the designers of empirical disposition, transformable dress has been evolving gradually. The feature of transformable design appeared in dress is considered as 'variability' which changes in the flow of time. Furthermore, the morphological variability and variability of material have been examined as visual stimuli and conversion of material. By analyzing and assorting diverse transformable dresses comprehensively, it could be divided into technique-oriented transformable design and transformable design with a wearer's intervention. The technique-oriented transformable design is subdivided into the conversion of material and the conversion of form; the transformable design with a wearer's intervention into the conversion of functional frame and the conversion of aesthetic feature.

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The Ultrasonic Treatment Characteristics of LiV$_3$O$_8$ by New Synthesis (새로운 합성법에 의한 LiV$_3$O$_8$ 의 초음파처리 특성)

  • 박수길;김종진;손원근;김상욱;류부형;이주성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.151-154
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    • 1998
  • The layered trivanadate, LiV$_3$O$_{8}$ has been investigated as a cathode material for secondary lithium batteries. Early in its development the preparation method of LiV$_3$O$_{8}$ strongly influenced its electrochemical properties, such as discharge capacity, rate capability and cycling efficiency. In the present experiment, a new synthesis route has been applied to obtain LiV$_3$O$_{8}$ . Instead of the conventional high temperature technique leading to the crystalline form, a solution technique producing the amorphous form has been used. This material, after dehydration, shows an electrochemical performance exeeding that of the crystalline one. The rationale for this behavior mainly lies in microscopic factors, i.e., in the possibility for the unit cell of amorphous LiV$_3$O$_{8}$ to insert up to 9 Li$^{+}$, instead of six for crystalline LiV$_3$O$_{8}$ . The ultrasonically treated products in water were characterized by XRD, TGA, DSC, and SEM. These measurements showed that the ultrasonic treatment process of crystalline LiV$_3$O$_{8}$ causes a decrease in crystallinity and considerable increases in specific surface area and interlayer spacing.g.

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Deflection and vibration analysis of higher-order shear deformable compositionally graded porous plate

  • Ebrahimi, Farzad;Habibi, Sajjad
    • Steel and Composite Structures
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    • v.20 no.1
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    • pp.205-225
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    • 2016
  • In this study the finite element method is utilized to predict the deflection and vibration characteristics of rectangular plates made of saturated porous functionally graded materials (PFGM) within the framework of the third order shear deformation plate theory. Material properties of PFGM plate are supposed to vary continuously along the thickness direction according to the power-law form and the porous plate is assumed of the form where pores are saturated with fluid. Various edge conditions of the plate are analyzed. The governing equations of motion are derived through energy method, using calculus of variations while the finite element model is derived based on the constitutive equation of the porous material. According to the numerical results, it is revealed that the proposed modeling and finite element approach can provide accurate deflection and frequency results of the PFGM plates as compared to the previously published results in literature. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as porosity volume fraction, material distribution profile, mode number and boundary conditions on the natural frequencies and deflection of the PFGM plates in detail. It is explicitly shown that the deflection and vibration behaviour of porous FGM plates are significantly influenced by these effects. Numerical results are presented to serve as benchmarks for future analyses of FGM plates with porosity phases.

Improving the Skin Penetration of Cosmetics Containing Omega 3 Fatty Acids

  • KIM, Han-Sook;HAN, Sien-Ho
    • Journal of Wellbeing Management and Applied Psychology
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    • v.4 no.4
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    • pp.15-25
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    • 2021
  • Purpose: The purpose of this study is to form a new cosmetic market through the development of a composition with high skin permeability after adding omega 3 to Aloe Vera soothing gel products. Research design, data and methodology: In this study, omega-3 fatty acids were added to cosmetic products in the form of soothing gels. By applying nanoparticle technology to rapidly increase the penetration of raw materials into the skin, characteristics related to skin moisture and regeneration were determined. Omega-3 was used as a raw cosmetic material. Then 5% and 15% nanoparticle aqueous products containing omega-3 were prepared. The developed water hydrate was subjected to skin permeability test using artificial skin. Results: 53 hours of artificial transdermal penetration of the developed composition, the ethanol-based omega-3 containing nanoparticle solubilized raw material was about three times higher penetration than the ethanol-based omega-3 containing nanoparticle solubilized raw material. Conclusions: The raw material product (SR-1901) containing 5% of omega-3 nanoparticle water hydrate has skin regeneration ability and pain reduction effect. It can be expected that the skin cosmetics market will be reorganized into a new distribution structure and opportunity through omega-3 supplemented soothing gel cosmetics with improved efficacy than existing cosmetics.

A study on naturalism style of fashion-concentrating on the 1990s- (복식의 자연주의 양식에 관한 연구-90년대 현대 복식을 중심으로-)

  • 이경아;전혜정
    • Journal of the Korean Society of Costume
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    • v.37
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    • pp.253-273
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    • 1998
  • The culture reflects the ideology of a particular period in time and such values change according to the needs and requests of that time which eventually becomes an important factorin forming the exterior. The clothing is part of a way that composes and expresses the inherent substance of society and culture. Also, the clothing itself manifests the artistic values and behavior of mankind as an external structure maintaining its place as a big part in culture. The purpose of this study are to elucidat the concept of naturalism, which is discussed in many facets in the modern era; I studied the concept as well as the history of naturalism in order to manifest the meaning of clothing in the context of culture and I explained the concept in terms of the modern era. On such ground, I explained the naturalism expressed through clothing and characterized the exter-nal form of clothing. Also, in order to know the stream of naturalism in the modern context, I referred to the Vogue magazine of the 90s, using Delong's ABC method. Naturalism, in the context of modern fashion is a way to express the nostalgia of nature's vi-ability and purity of ecology apart from the artificial and structural appearance that resulted form scientific enhancement and hence, the ecological crisis. Naturalism pursues the soft- ness and comfort of the natural silhouette, color and material of the human body and it can be said that naturalism emphasizes the mix-ture of three substances : human, nature and clothing. The naturalism can be characterized by the factors expressed in clothing as follows. First, the naturalism shown in the form it-self draws the beauty of the bodyline without any reduction nor exaggeration. Without any distorttion of the human bodyline it shown the curve as one moves along, using the soft material. Second, the naturalism shown in color most-ly uses the natural tone with added white color and other color low in intensity and value like the receded colors of the earth that could be compared to the beauty of ecru. Third, the naturalism shown in the material is thin, light and soft in texture. In order to bring out the most natural curve of the human body, the natural fiber becomes the main material, sometimes, using crude materials. Due to the lindustrial improvement, softness and elasticity is added to the natural fibers giving them an important role as materials. Fourth, the naturalism shown in textile depicts the real natural objects in life. According to my study, the personality of naturalism in modern clothing was shown to be most strong in material and then in the order of form, texture and textile. The material com-posed of the natural silhouette and natural fibers were used to make soft color. In form, Paul Poiret made appearance expressing the natural beauty of the human body without the corset ; it continued with the inner lining making the clothing hard but in the 90s, lining-less, extremely exposed clothes and knit wear is used to emphasize the natural beauty of the body. In color and textile, the tendency spok-en above is not as strong but in color, instead of high intensity or value, the usage of neutral colors with added white color or ecru color, ear-th tone is increasing. In textile, the usage of flowers as natural material is seen frequently. As a whole, naturalistic trend in the 90s is increasing and the modern fashion is breaking out from the artificial and architectural form and conforming to a form that can realize the natural beauty of the human body. And the natural color and textile that conforms to such ideas are being used to pursue the human oriented trend that has appeared due to the increase in usage of soft natural fiber. Nowadays, the idea of returning to nature, defying the artificiality, desiring the leisure and psychological abundance that can be explained as naturalistic way of thinking is necessitated in this modern era as long as humans coexist with nature, this tendency will continue in clothing.

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Proper Mixing Ratio for Securing Quality of Free-form Panel (비정형 패널의 형상 품질확보를 위한 적정 배합비 도출)

  • Kim, Min-Sik;Park, Chae-Wool;Kim, Ki-Hyuk;Do, Sung-Lok;Lee, Dong-Hoon
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.5
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    • pp.449-456
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    • 2019
  • Recent developments in architectural technologies and programs have enabled architects to think creatively and design free-form architecture. however, there are many problems in the production technology of FCP(Free-Form Concrete Panel). In particular, reduced accuracy due to lack of free-form panel production technology can lead to redesign of buildings as a result, problems such as an increase in construction cost and period. Therefore, this experiment aimed to compensate the decrease of the accuracy according to the displacement difference and to derive the proper mixing ratio for maintaining the shape during the free-form panel curing. In this study, molds were made using paraffin that is a recyclable phase change material. Concrete Panel is usually produced from Portland cement, dead burn magnesia, phosphate, borax and fine aggregate. In this study, four mixing ratios of FCP were selected after each material was blended to determine the proper blending ratio of the fluidity phase, the water absorption rate and the water content of the test piece. FCP was fabricated on the basis of the selected four compounding ratios and thickness and error rate were measured. Based on the error rate of the measured FCP, the quality standard was satisfied among the four compounding ratios.

Investigation and Numerical Analysis of Node Connectors in Free-Form Spatial Structures

  • Hwang, Kyung-Ju;Park, Don-U;Park, Sun-Woo;Knippers, Jan
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.3 s.25
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    • pp.87-95
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    • 2007
  • The recent completions of free-form spatial structures provide us a very attractive form. To realize such an extraordinary shape, it is absolutely necessary that the connector systems have to be investigated the characteristics of the systems and analyzed with a practicable method. In this context, this research consists of not only literature research but also numerical analysis with selected connector systems, which was adopted in real free-form spatial structures. For numerical analysis, especially, finite element analysis (FEA) is performed with a various test parameter using a commercial program ANSYS. Consequently, the general characteristics of node connectors the moment-rotation-curves are presented by considering a large deformation effect as well as a multi-linear material properties.

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